The present invention relates to tape sealing a carton with a tape length course extending between a first location on the carton e,g., a front end and a second location, e.g., a rear end, and refers more particularly to forming a readily, digitally manipulated pull tab in the tape at one or both locations on the carton and with which the applied tape length can be stripped off the carton with pulling force applied thereto by means of the pull tab.
It is common practice to tape seal rectangular shipping cases or cartons with a continuous length of sealing tape, such as a pressure sensitive type, the tape being applied first at the front wall of the carton, onto and along either or both the bottom or top wall if upper and lower sealing courses are used, and then onto the rear wall, the tape courses along the top and bottom walls overlapping and sealing infolded closure flaps in place on the carton. The tape applied at the front and rear walls provides an anchorage length to securely hold the tape lay down at the top and bottom walls so that, e.g., any imposed loading of carton contents on the bottom wall cannot breach the tape seal along that surface or the top flaps cannot readily accidentally become opened. The anchorage lengths of tape applied to the front and rear walls of the carton will preferably be at least about 2 inches although longer lengths can be used as can shorter ones where carton sizes and loadings are of reduced magnitude. Most usually though, these anchorage lengths will be at least 2 inches.
As the tape in a given sealing course is being applied to the carton, it will be pressed firmly against the carton surfaces to provide good and uniform adhesion of the adhesive face of the tape to such surfaces including at the initial and terminal points of the tape course. Generally then it will not be possible for a person who wishes to open the carton to remove contents, to simply peel the tape course from the carton starting at one of the tape course ends, since the degree of tape adhesion is high and this is difficult to overcome with finger effected peeling force. Commonly a knife or similar sharp instrument will be employed by the person to slit the tape. This procedure can result in damage to products within the carton.
The use of a pull tab as an initiator for tear stripping cellophane wrappings on products of various descriptions is well known. The tearable strip on these wrappings is of course, not adhered to the product and the tear action is easily achieved. A device and manner for forming a pull tab on a carton sealing tape length at an end of the tape length is known. Such device, made by the Bemis Company of Minneapolis, Minn., folds back a terminal length of the adhesive face pressure sensitive against itself so the fold back becomes adhered leaving non-adhesive opposite faces at the fold back so that this fold back becomes a non-adhered tape pull tab on the carton. This device and manner of forming a pull tab has a number of disadvantages, viz.,
a. The fold back of the tape itself is wasteful of tape. PA1 b. A pull tab is formed only at one end of the tape course--which fact would render the pull tab useless for tape stripping purposes if a large or heavy carton had the pull tab end disposed in an inaccessible disposition, as for example, abutting the end of another carton. PA1 c. The pull tab because it is formed solely of pressure sensitive tape is somewhat stiffened and has a very smooth surface at both sides so it does not tend to sit close to the carton wall--this condition could allow for self-peeling of the associated tape anchorage run due to transportation jostling of the carton and especially where the carton is in close shipping contact with other cartons. PA1 d. The pull tab uses a printed indicia denotive of its function. Since many of the pressure sensitive tapes are semi-transparent and very shiny, this indicia is hard to see.
It is therefore desirable that an improved method and apparatus be provided for forming sealing tape pull tabs on taped cartons and which method and apparatus do not have the undesirable shortcomings noted above.